SnazzyLabs

LateC300, glad to hear that you noticed a difference. I'm not disappointed in the C300 stock, but it certainly isn't a "hoot" as you say. I know there is a little more power I can squeeze out of it and I'm willing to pay for it. I'm partial to the ECU tunes (albeit more expensive) because I won't have to remove it when I go in to service it, but mailing my ECU makes me uneasy and I don't want have to do it multiple times in the future if the dealership flashes over the top of it when servicing. I'll probably opt in for the BMS. You say that you noticed a difference between using the brown (4th) tricky-to-access plug vs the standard 3 plugs using 91 octane fuel?

Shadwell

I ended up removing the TMAP Sensor from the inlet pipe assy as the connctor block and terminal were such a sod to get at.. with a torx screw i removed the sensor stil conncted to the harness..
i attached the tuner harness (which is easier as its extended and with the senosr body out of the way you have better acces to the other haness end.. then re-fitted the sensor..
At no time was access for any of this anything other than crap..
5 mins job is in reality a good hour.. (this was on a race chip ultimate which only taps MAP and TMAP...
BMS also does fuel rail pressure and cam position i believe, but these are a doddle to access....

LateC300

never ran it with just the 3 plugs, but it was a big difference over stock with all 4 plugs. plus you can run e85

yea the whole removal process took me an hour, installing it would probably take just as long since ive seen/done it twice already. if it were my first trying to find out how/where to install that 4th plug, i would have probably just lit the car on fire

Str8Down

Isn't BMS only like 20hp? I wouldn't think you could even feel that

LateC300

the peak hp feels like it's about that much, not even noticeable really, our tiny turbos really putter out in the top end.

the real gains are torque/hp gains in the lower powerband (1.7k-4k RPMs). It feels almost 50tq more all the way through, it's quite a bit of difference when you're short shifting and whizzing through town or traffic

Tartan43

Well the ECU is back from OE Tuning and dyno numbers don’t do it justice. The car is so much more responsive especially in the lower and mid RPM range, where I use it most. The throttle is borderline hair-trigger sensitive. Even the engine sounds throatier in the mid range under full throttle acceleration – love it! The only thing that seems to remain the same are the shift points in all the DYNAMIC SELECT modes.

I had the stock ECU Dyno tested last Saturday afternoon at MAC Autosport in Parker Colorado. Nick McMahan was very knowledgeable and helpful, explaining how the Dyno was set up, all the values it can capture, and the exact procedure for Dyno-ing an all wheel drive car. The air temperature in the garage was around 93 °F. The dyno was set to SAE configuration to compensate for barometric pressure and altitude and recorded max 200.72whp and max 285.18 Torque (see the blue lines on the chart below)

I’m not sure how to explain the higher bhp and torque numbers except to guess that Mercedes publishes conservative max values and some engines perform slightly better. Using the same 25% loss I assumed for the BMS Dyno results in the earlier post, this engine produced around 266bhp – about 10% more power than Mercedes claims.

On Monday afternoon I email Rocco at OE Tuning to make sure they can flash the ECU the next day. Within minutes I received a reply confirming that they have time to do it. I FedEx’d the ECU for a 10:30am delivery to Huntington Beach and forwarded the tracking number to Rocco. Again within minutes I got an acknowledgement and a promise to be notified as soon as they receive the ECU.

Tuesday at 10:30am PST I received a call from OE Tuning that they have my ECU and are beginning to program it. Several hours latter I received another call telling me everything went well, the ECU is boxed and scheduled to be picked up by FedEx shortly.

Wednesday at exactly 10:30am the ECU was back in my possession looking identical to how it left Denver two days prior (I took pictures). A few minutes later my car idling smoothly in my garage.

Thursday afternoon I went back to MAC Autosport. Nick seemed as excited as me to see the result of the tune. The car was strapped down and put into Dyno mode. The air temperature in the garage that day was 6 °F higher around 99 °F. The dyno was set to SAE to compensate for barometric pressure and altitude and this time recorded max 227.66whp and max 317.10 Torque (see the Red lines on the chart below). Again using the 25% power loss for an all wheel drive C300, that translated to approximately 303bhp – a gain of only 37bhp.



OE Tuning claimed 60bhp (50bhp worse case) so what happened?... I know these results are hardly scientific; dyno tests are 5 days apart, 6 °F ambient temperature difference, heatsoak after several pulls, etc. or maybe I’m doing something wrong and someone reading this post can correct my assumptions and math.

A 37bhp ECU tune ($17 per 1HP gain) is really nothing to be disappointed about, especially when you see the consistent gains through the entire range, but OE Tuning set the expectation so high…

Hope this write up was at all helpful.

DapperStyle

If 50 bhp worst case is before calculating the loss then 50 bhp - 25% loss is right around 38 bhp.

Tartan43

50bhp is around 38whp, unfortunately as you can see from the dyno results the car only added 27whp or about 37bhp.

racerrex

Hey Tartan,

I'm in Highlands Ranch and just picked up my C300 4MATIC Sport from Littleton. Aside from the dyno numbers, how does the butt dyno feel to you? You feel a significant difference?

Thanks!

Tartan43

Hey Racer, as I said the dyno numbers don't do it justice. The car feels more powerful and responsive. Since we're practically neighbors, PM me if you'd like to do a few side by side runs. Maybe run up the switchbacks in Morrison or Lookout.

racerrex

That be awesome! When I had my E46 M3. I used to run with the BMW guys and do the Deer Creek Canyon run.

Wkar275

Thank you very much for taking the time to post the results and feedback. I am slightly disappointed in OE tunings claim. For that price I will probably be purchasing the BMS piggyback. Where I don't have to wait for the ecu either. I think that horsepower figure is a great start for the tuning community for the engine I just am not that impressed one bit. As all these tuners claim 60 bhp is the magic mark meanwhile it's half.

Tartan43

Agree OE Tuning likely overstated the tune results somewhat, similar observation on the C450AMG.com site (http://c450amg.com/product-review/oetuning), but consider the following:

1. 99 °F ambient temperature during the dyno pulls
2. 37bhp is still 16-17bhp better than a 20-21bhp piggyback solution - an additional 20% hp gain is huge for the relatively low investments we're talking about with these mods
3. Consider the power range you get and the fact that peak hp is present from about 4.5K RPM through 5.25K (just when the stock tune is tapering off)

In the end suffice it to say I'm very happy with the results.

InTheBenz0

25% drivetrain loss is a bit too much for an auto. I use 20% for auto and 15% for manual gearbox

Tartan43

I guessed conservatively as I'm "blessed" with both an Automatic and a 4MATIC. What percentage drivetrain loss should I have used for this setup?

InTheBenz0

20% is what I would still use. There are many cars with awd... audi S6 and RS7, folks tuning the new E63, and BMW with X5M and X6M cars.

Standard on all of these that I have seen are 20% usage. So I would use 20%.

Tartan43

Snazzy, here's another alternative I recently came across: Weistec ECU tune 217whp and 270wtq.

http://weistec.com/all/c/c300/2015-p...u-upgrade.html

SoDakBenz

It's worth noting their dyno chart says with their tune and downpipe

z8achoc18

Thanks for the data points. This is really helpful as I'm looking into getting the OE tune for my W205 C300 4Matic.

What's your 0-60 time looking like?

15MBC300

http://weistec.com/all/c/c300/2015-p...a-adapter.html

Tartan43

good catch - I didn't notice the caption... Even more underwhelming considering the lower whp and wtq results as compare to other tunes (PP-Performance, OE Tuning) w/o the $400 investment in a downpipe.

SoDakBenz

If you have a down pipe and tune installed and your still only adding 9hp and like 17tq over stock I'm guessing they are accurate numbers but very disappointed. I was interested in getting the downpipe but not anymore if that's all that it produces even with a tune

LateC300

remember, a downpipe really benefits with high boost. these tunes arent going to blow your turbo up with too much boost, so the added benefits of modifying the exhaust (which is already pretty good from factory) are not that much.

if you were doing a turbo swap with like a CLA/GLA45 turbo, then maybe worth it...but at that point you're really going into fringe C-class territory

SnazzyLabs

I would agree that's a rather good improvement for the price. Not 60hp, but better than the BMS piggyback it seems. I appreciate the time you've taken to answer questions and foot the cost and annoyance of doing dynos.

I'll probably pull the trigger when I get back in town. I retrospect, I should have taken advantage of the sale. Lol. Oh well.

SnazzyLabs

I think I'm going to pull the trigger this week. Any regrets?